I exported a BibTeX file from the journal's website, and in the title, there was a chemical formula written like this
Na<inf>2</inf>Mn<inf>3</inf>(SO<inf>4</inf>)<inf>4</inf>
I copied and pasted the content of BibTeX file to my reference.bib file and executed. The problem is
Na<inf>2</inf>Mn<inf>3</inf>(SO<inf>4</inf>)<inf>4</inf>
appeared in pdf output. I would like to ask which package should I use for a chemical formula written like this?



mhchemthen this chemical formula can be typeset with\ce{Na2Mn3(SO4)4}. There are other packages also used for chemical formulae but I'm not familiar with them. See this question (https://tex.stackexchange.com/questions/145838/typesetting-chemical-formulas) for more. – Willoughby Sep 04 '21 at 02:31